Conventionally when packaging a semiconductor device, each bonding point of the IC chip to be packaged is connected with an inner lead through a bonding wire (such as a gold wire). Because each outer lead which is an extension of an inner lead can be welded into a connection point of a circuit board, a signal path can thus be built to conduct signal between a bonding point of the packaged IC chip and a corresponding connecting point of the circuit board. To prevent the bonding wire from being touched or hurt, encapsulant such as epoxy is used to cover the top of the IC chip. Due to possible existence of internal stress caused by the difference in coefficient of thermal expansion, a conventional IC package which usually lacks stress buffer capability tends to crack easily or to have its bonding wire broken away from its bonding point, resulting in bad application reliability of the IC. An IC chip without proper protection for either itself or its leads will likely be hurt or damaged by external force inherent in production process or shipping process, resulting in high failure rate of the IC. A conventional IC package with leads often deformed by external force or pressure needs work to recover the normal position of its leads, or to put its leads in order before welding them into another device such as a circuit board, leading to waste of labor and time in applying the IC. It can be seen now that there are disadvantages inherent in a conventional IC package structure, and there's a need of developing a new structure for overcoming these disadvantages.